Factors associated with Clostridium difficile diarrhea in a hospital in Beijing,China

Clostridium difficile is the most common cause of hospital-acquired diarrhea in patients treated with antibiotics, chemotherapeutic agents, and other drugs that alter the normal equilibrium of the intestinal flora. A better understanding of the risk factors for C. difficile-associated disease (CDAD) could be used to reduce the incidence of CDAD and the costs associated with its treatment. The aim of this study was to identify the risk factors for CDAD in a cohort of Chinese patients in a Beijing hospital. Medical charts of a total of 130 inpatients (62 males and 68 females) with hospital-acquired diarrhea (45 with CDAD; 85 without CDAD) were retrospectively reviewed. C. difficile toxins A and B were detected in fecal samples using enzyme-linked fluorescence assays. The drugs used by patients with and without CDAD before the onset of diarrhea were compared. Factors that differed significantly between the two groups by univariate analysis were analyzed by multivariate analysis using a logistic regression model. Multivariate analysis showed that cephalosporin treatment was associated with a significantly higher risk of CDAD in hospitalized patients, while treatment with glycopeptides was significantly associated with a reduction in CDAD (P<0.001 for cephalosporin; P=0.013 for glycopeptides). Our data confirmed previous findings that empirical treatment with cephalosporins is positively associated with CDAD compared to individuals using other CDAD-related drugs. Additionally, we showed that treatment with glycopeptides was negatively associated with CDAD, compared to individuals using other CDAD-related drugs.     

Risk factors for recurrence of Clostridium difficile infection: effect of vancomycin-resistant enterococci colonization

Recurrent Clostridium difficile infection (CDI) is one of the most difficult problems in healthcare infection control. We evaluated the risk factors associated with recurrence in patients with CDI. A retrospective cohort study of 84 patients with CDI from December 2008 through October 2010 was performed at Pusan National University Yangsan Hospital. Recurrence occurred in 13.1% (11/84) of the cases and in-hospital mortality rate was 7.1% (6/84). Stool colonization with vancomycin-resistant enterococci (VRE) (P = 0.006), exposure to more than 3 antibiotics (P = 0.009), low hemoglobin levels (P = 0.025) and continued use of previous antibiotics (P = 0.05) were found to be more frequent in the recurrent group. Multivariate analysis indicated that, stool VRE colonization was independently associated with CDI recurrence (odds ratio, 14.519; 95% confidence interval, 1.157-182.229; P = 0.038). This result suggests that stool VRE colonization is a significant risk factor for CDI recurrence.     

Evaluation of a Chromogenic Culture Medium for the Detection of Clostridium difficile

Purpose

Clostridium difficile (C. difficile) is an important cause of nosocomial diarrhea. Diagnostic methods for detection of C. difficile infection (CDI) are shifting to molecular techniques, which are faster and more sensitive than conventional methods. Although recent advances in these methods have been made in terms of their cost-benefit, ease of use, and turnaround time, anaerobic culture remains an important method for detection of CDI.

Materials and Methods

In efforts to evaluate a novel chromogenic medium for the detection of C. difficile (chromID CD agar), 289 fecal specimens were analyzed using two other culture media of blood agar and cycloserine-cefoxitin-fructose-egg yolk agar while enzyme immunosorbent assay and polymerase chain reaction-based assay were used for toxin detection.

Results

ChromID showed the highest detection rate among the three culture media. Both positive rate and sensitivity were higher from chromID than other culture media. ChromID was better at detecting toxin producing C. difficile at 24 h and showed the highest detection rate at both 24 h and 48 h.

Conclusion

Simultaneous use of toxin assay and anaerobic culture has been considered as the most accurate and sensitive diagnostic approach of CDI. Utilization of a more rapid and sensitive chromogenic medium will aid in the dianogsis of CDI.     

Diagnostic accuracy of loop-mediated isothermal amplification in detection of Clostridium difficile in stool samples: a meta-analysis

Introduction

Clostridium difficile infection (CDI) remains a diagnostic challenge for clinicians. More recently, loop-mediated isothermal amplification (LAMP) has become readily available for the diagnosis of CDI, and many studies have investigated the usefulness of LAMP for rapid and accurate diagnosis of CDI. However, the overall diagnostic accuracy of LAMP for CDI remains unclear. In this meta-analysis, our aim was to establish the overall diagnostic accuracy of LAMP in detection of Clostridium difficile (CD) in stool samples.

Material and methods

A search was done in PubMed, MEDLINE, EMBASE and Cochrane Library databases up to February 2014 to identify published studies that evaluated the diagnostic role of LAMP for CD. Methodological quality was assessed according to the quality assessment for studies of diagnostic accuracy (QUADAS) instrument. The sensitivities (SEN), specificities (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) were pooled statistically using random effects models. Statistical analysis was performed by employing Meta-Disc 1.4 software. Summary receiver operating characteristic (SROC) curves were used to summarize overall test performance. Funnel plots were used to test the potential publication bias.

Result

A total of 9 studies met inclusion criteria for the present meta-analysis. The pooled SEN and SPE for diagnosing CD were 0.93 (95% CI: 0.91–0.95) and 0.98 (95% CI: 0.98–0.99), respectively. The PLR was 47.72 (95% CI: 15.10–150.82), NLR was 0.07 (95% CI: 0.04–0.14) and DOR was 745.19 (95% CI: 229.30−2421.72). The area under the ROC was 0.98. Meta-regression indicated that the total number of samples was a source of heterogeneity for LAMP in detection of CD. The funnel plots suggested no publication bias.

Conclusions

The LAMP meets the minimum desirable characteristics of a diagnostic test of SEN, SPE and other measures of accuracy in the diagnosis of CD, and it is suitable as a rapid, effective and reliable stand-alone diagnostic test for diagnosis of CDI, potentially decreasing morbidity and nosocomial spread of CD.     

Epidemiology and clinical characteristics of Clostridium difficile infection in a Korean tertiary hospital

In order to investigate the incidence, clinical and microbiologic characteristics of Clostridium difficile infection (CDI) in Korea, a prospective observational study was performed. From September 2008 through January 2010, all patients whose stool was tested for toxin assay A&B and/or C. difficile culture were studied for clinical characteristics. Toxin types of the isolates from stool were tested. The mean incidence of CDI per 100,000 patient-days was 71.6 by month (range, 52.5-114.0), and the ratio of CDI to antibiotic-associated diarrhea was 0.23. Among 200 CDI patients, 37.5% (75/200) was severe CDI based on severity score. Clinical outcome of 189 CDI was as followed; 25.9% (49/189) improved without treatment, 84.3% (118/140) achieved clinical cure and attributed mortality was 0.7% (1/140) with the treatment. Recurrence rate was 21.4% (30/140) and cure without recurrence was 66.4% (93/140). The most common type of toxin was toxin A-positive/toxin B-positive strain (77.5%), toxin A-negative/toxin B-positive strains or binary toxin-producing strains comprised 15.4% or 7.1%, respectively. In conclusion, the incidence of CDI in Korea is a little higher than other reports during the non-epidemic setting. We expect that the change of epidemiology and clinical severity in CDI can be evaluated based on these results.     

The First Case of Antibiotic-associated Colitis by Clostridium difficile PCR Ribotype 027 in Korea

Clostridium difficile (C. difficile) is a common causative agent of pseudomembranous colitis (PMC). C. difficile-associated diarrhea (CDAD) ranges from mild diarrhea to life threatening PMC. Recently, a highly virulent strain of C. difficile polymerase chain reaction ribotype 027 was found in North America, Europe, and Japan. A 52-yr-old woman with anti-tuberculosis medication and neurogenic bladder due to traffic accident experienced five episodes of C. difficile PMC after taking antibiotics for pneumonia along with septic shock and acute renal failure. She was readmitted to the intensive care unit and treated with oral vancomycin with refractory of oral metronidazole, inotropics and probiotics for over 60 days. C. difficile isolated both at the first and the last admission was identified as C. difficile ribotype 027 by ribotyping, toxinotyping, and tcdC gene sequencing, which turned out the same pathogen as the epidemic hypervirulent B1/NAP1 strain. This is the first case of C. difficile PCR ribotype 027 in Korea. After discharge, she was maintained on probiotics and rifaximin for 3 weeks. She had no relapse for 6 months.     

Release of TcdA and TcdB from Clostridium difficile cdi 630 is not affected by functional inactivation of the tcdE gene

The small open reading frame tcdE is located between the genes tcdA and tcdB which encode toxin A (TcdA) and B (TcdB), respectively, within the pathogenicity locus of Clostridium difficile. Sequence and structure similarities to bacteriophage-encoded holins have led to the assumption that TcdE mediates the release of the toxins from C. difficile into the extracellular environment. A TcdE-deficient C. difficile 630 strain was generated by insertional inactivation of the tcdE gene. Data revealed that TcdE does not regulate or affect growth or sporogenesis. TcdE-deficiency was accompanied by a moderately increased accumulation of TcdA and TcdB prior to sporulation in this microorganism. Interestingly, this observation did not correlate with a delayed or inhibited toxin release: inactivation of TcdE neither significantly altered kinetics of release nor the absolute level of secreted TcdA and TcdB, indicating that TcdE does not account for the pathogenicity of C. difficile strain 630. Furthermore, mass spectrometry analysis could not reveal differences in the secretome of wild type and TcdE-deficient C. difficile, indicating that TcdE did not function as a secretion system for protein release. TcdE was expressed as a 19 kDa protein in C. difficile, whereas TcdE expressed in Escherichia coli appeared as a 19 and 16 kDa protein. Expression of the short 16 kDa TcdE correlated with bacterial cell death. We conclude that TcdE does not exhibit pore-forming function in C. difficile since in these cells only the non-lytic full length 19 kDa protein is expressed.     

Extra-intestinal infections caused by Clostridium difficile

The objective of this paper was to investigate the incidence of extra-intestinal infections caused by Clostridium difficile. During a 10-year period, the microbiology laboratory of our institution isolated 2034 isolates of C. difficile . Of the 2034 isolates, 21 (1.08%) were obtained from extra-intestinal sources. This represents an incidence of extra-intestinal isolation of four cases per 100 000 admissions. We were able to review the records of 17 patients for our study. The isolates in 12 patients were obtained from structures or fluids anatomically close to the colon and included the following infections: peritonitis in five cases (three primary and two secondary), intra-abdominal abscesses in three patients and abdominal wound infections in four cases. The infections in the other five patients were not in the anatomic vicinity of the colon. They included one case with a brain abscess, two episodes of bacteremia and two cases of foot infections (one chronic osteomyelitis). In all but one case, C. difficile isolation was obtained as part of a polymicrobial flora. The isolates were frequently non-toxigenic and the extra-intestinal infections occurred without concomitant diarrhea or prior anti-microbial therapy. Out of the 17 patients, eight died and nine survived. Death could not be directly attributed to C. difficile in any of the cases. The isolation of C. difficile outside the intestinal tract is very uncommon. Its clinical significance should be interpreted with caution.     

A case of pseudomembranous colitis after voriconazole therapy

This is a case report on a 35-year-old man with acute myelogenous leukemia who presented fever and intermittent mucoid loose stool to the emergency center. He had been taking voriconazole for invasive pulmonary aspergillosis. The flexible sigmoidoscopy was consistent with the diagnosis of pseudomembranous colitis.     

Epidemiological and pathobiological profiles of Clostridium perfringens infections: review of consecutive series of 33 cases over a 13-year period

Background: Although Clostridium perfringens (C. perfringens) is well known as the causative agent of several forms of enteric disease, precise epidemiological and pathobiological aspects are still unknown. Methods: We retrospectively reviewed the culture results of samples collected in our hospital from 2001 through 2013. In addition, for the detection and toxinogenic typing of C. perfringens, polymerase-chain-reaction amplification (PCR)-based rapid analysis was performed in 6 cases using DNA extracted from paraffin-embedded tissues. Results: A total of 35 samples from 33 cases were positive for C. perfringens, representing an incidence of 0.017% (35/205, 114). Among 33 patients, 21 patients manifested sepsis and 7 patients had bacteremia. One of the septic cases was complicated by fatal intravascular hemolysis and thus, the prevalence was estimated at 3.0% among C. perfringens infections (1/33). The direct causative disease or state for C. perfringens infection was identified in 18 patients: surgery or intervention for cancers, 8 patients; chemotherapy for cancer, 2 patients; surgery or intervention for non-neoplastic disease, 6 patients; liver cirrhosis, 3 patients, etc. PCR-based toxinogenic typing of C. perfringens detected the alpha-toxin gene only in tissue from a patient who died of massive hemolysis; none of the toxin genes could be amplified in the other 5 cases examined. Conclusions: The prevalence of overt C. perfringens infection is low, but upon detection, infected patients should be carefully monitored for fatal acute hemolysis caused by type A C. perfringens. Furthermore, PCR-based rapid detection of C. perfringens and toxinogenic typing by archival pathological material is applicable as a diagnostic tool.     

Clinical and microbiological characteristics of community-onset Clostridium difficile infection in The Netherlands

To elucidate the prevalence, characteristics and risk factors of community-onset Clostridium difficile infection (CO-CDI), an uncontrolled prospective study was performed. For 3 months in 2007–2008, three laboratories in The Netherlands tested all unformed stool samples submitted by general practitioners (GPs) for C. difficile by enzyme immunoassay for toxins A and B, irrespective of whether GPs specifically requested this. Patients with positive results were asked to complete a questionnaire. Positive stool samples were cultured for C. difficile , and isolates were characterized. In all, 2443 stool samples from 2423 patients were tested, and 37 patients (1.5%) with positive toxin test results were identified. Mixed infections were not found. Age varied from 1 to 92 years, and 18% were under the age of 20 years. Diarrhoea was typically frequent and watery, sometimes with admixture of blood or fever. Eight of 28 patients (29%) suffered recurrences. Among 31 patients with toxin-positive stool samples for whom information was available, 20 (65%) had not been admitted to a healthcare institution in the year before, 13 (42%) had not used antibiotics during the 6 months before, and eight (26%) had neither risk factor. A separate analysis for patients whose samples were both toxin-positive and culture-positive produced similar results. Cultured C. difficile isolates belonged to 13 different PCR ribotypes, and 24% of the isolates were non-typeable (rare or new) PCR ribotypes. In conclusion, CO-CDI can affect all age groups, and many patients do not have known risk factors. Several PCR ribotypes not encountered in hospital-associated outbreaks were found, suggesting the absence of a direct link between outbreaks and community-onset cases.     

Interleukin‐23 (IL‐23), independent of IL‐17 and IL‐22, drives neutrophil recruitment and innate inflammation during Clostridium difficile colitis in mice

Our objective was to determine the role of the inflammatory cytokine interleukin‐23 (IL‐23) in promoting neutrophil recruitment, inflammatory cytokine expression and intestinal histopathology in response to Clostridium difficile infection. Wild‐type (WT) and p19^−/− (IL‐23KO) mice were pre‐treated with cefoperazone in their drinking water for 5 days, and after a 2‐day recovery period were challenged with spores from C. difficile strain VPI 10463. Interleukin‐23 deficiency was associated with significant defects in both the recruitment of CD11b^High Ly6G^High neutrophils to the colon and the expression of neutrophil chemoattractants and stabilization factors including Cxcl1, Cxcl2, Ccl3 and Csf3 within the colonic mucosa as compared with WT animals. Furthermore, the expression of inflammatory cytokines including Il33, Tnf and Il6 was significantly reduced in IL‐23‐deficient animals. There was also a trend towards less severe colonic histopathology in the absence of IL‐23. The induction of Il17a and Il22 was also significantly abrogated in IL‐23KO mice. Inflammatory cytokine expression and neutrophilic inflammation were not reduced in IL‐17a‐deficient mice or in mice treated with anti‐IL‐22 depleting monoclonal antibody. However, induction of RegIIIg was significantly reduced in animals treated with anti‐IL‐22 antibody. Taken together, these data indicate that IL‐23, but not IL‐17a or IL‐22, promotes neutrophil recruitment and inflammatory cytokine and chemokine expression in the colon in response to C. difficile infection.     

The emergence of ‘hypervirulence’ in Clostridium difficile

The impact of Clostridium difficile-associated disease (CDAD) in healthcare settings throughout the developed world is considerable in terms of mortality, morbidity, and disease management. The incidence of CDAD has risen dramatically since the turn of this century, concomitant with the emergence of so-called hypervirulent strains which are thought to cause a more severe disease, higher relapse rates, and increased mortality. Pre-eminent amongst hypervirulent strains are those belonging to ribotype 027, which were first reported in Canada in 2003 and shortly thereafter in the UK. Since its arrival in Europe, it has spread rapidly and has now been reported in 16 member states and Switzerland. The physiological factors responsible for the rapid emergence of hypervirulent C. difficile strains remain unclear. It is known that they produce a binary toxin (CDT) in addition to toxins A and B, that they are resistant to fluoroquinolones due to mutations in gyrA, and that they are resistant to erythromycin. Representative strains have been suggested to produce more toxin A and B in the ‘laboratory flask’ (most likely due to a frameshift mutation in the repressor gene tcdC), to be more prolific in terms of spore formation, and also exhibit increased adherence to human intestinal epithelial cells due to altered surface proteins. However, the contribution of these and other as yet unidentified factors to the rapid spread of certain C. difficile variants (e.g., ribotypes 027 and 078) remains unclear at present. The advent of ClosTron technology means that it is now possible to construct genetically stable isogenic mutants of C. difficile and carry out reverse genetic studies to elucidate the role of specific gene loci in causing disease. The identification of virulence factors using this approach should help lead to the rational development of therapeutic countermeasures against CDAD.     

The roles of host and pathogen factors and the innate immune response in the pathogenesis of Clostridium difficile infection

Clostridium difficile (C. difficile) is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of pseudomembranous colitis. The clinical manifestation of C. difficile infection (CDI) is highly variable, from asymptomatic carriage, to mild self-limiting diarrhea, to the more severe pseudomembranous colitis. Furthermore, in extreme cases, colonic inflammation and tissue damage can lead to toxic megacolon, a condition requiring surgical intervention.     

A bile based study of Clonorchis sinensis infections in patients with biliary tract diseases in Ulsan, Korea

Stool examination is believed to be the most reliable method for detecting Clonorchis sinensis (CS) eggs. However, it has limited value for diagnosing clonorchiasis when the biliary tract is obstructed or when there is a light infection. We evaluated the infection states of CS in patients with biliary tract diseases using a bile sample. From January 2001 to August 2003, 238 patients who had undergone endoscopic biliary drainage were prospectively included in the study. The patients' bile samples were obtained directly from the nasobiliary drainage tube and then analyzed to detect CS eggs. The overall CS egg positive rate was 28.2% (35.4% in males, 19.4% in females). The egg positive rate was similar in all age groups examined: 26.7% in 30-39 years, 25.0% in 40-49 years, 24.4% in 50-59 years, 30.2% in 60-69 years, 35.3% in 70-79 years, and 25.0% in 80 years of age and over. There were no significant differences in the egg positive rate between the disease groups: 32.6% in bile duct cancer, 38.5% in gallbladder cancer, and 26.4% in gallstone diseases. Our results show that the CS infection rate was very high, regardless of the age, gender, and type of diseases of the patients. Although the study population was limited to patients with biliary tract diseases, it is assumed that clonorchiasis is still an endemic disease in Ulsan, Korea.     

Incidence,case fatality and genotypes causing Clostridium difficile infections,Finland, 2008

Since 2000, the epidemiology of C. difficile infections (CDI) has changed in the US and Europe. Few population-based assessments of both incidence and case fatality of CDI have been performed. In this study, the Finnish nationwide laboratory-based surveillance data from the year 2008 were analysed to assess the incidence and case fatality of CDI, and to detect regional differences in relation to molecular epidemiology. A total of 6201 episodes of CDI were identified (118.3/100000 population; range by regions, 57.2–189.1). The incidence increased by age and was highest in persons aged >84 years (1286.0). Of the CDI episodes, 711 (11.5%; range by regions, 2.2–15.0%) led to death within 30 days. The 30-day case fatality was highest (22.0%) in persons aged >84 years. In total, 334 (5% of all episodes) isolates from 13/21 regions were sent for genotyping: 120 (36%) were of PCR ribotype 027, and it was found in 6/13 regions. Among the rest of the isolates, 53 (16%) were of type 001, and 19 (6%) of 002 and 014. The incidence and case fatality were highest in elderly persons and varied regionally. This may be explained by uneven spread of hypervirulent PCR ribotypes, such as 027, but also differences in diagnostic activity or the patient populations among which the outbreaks are occurring.